Method for removing liners from cylinders



April 21, 1925- Patente-d pr. 21, 1925;v`

PAi'vlsl'a'r orner.

'- WILLIAM n., Woon, or'l WASHINGTON, nrs'rnwr or COLUMBIA.

mnrnonron nEMovING Y Application led ASeptember To all whom t mag/Iconaern.'

'Be it known that I, WILLIAM R. WOOD, a

citizen o-f the United States,'re`siding at` Washington, in ,the District of Columbia, have invented certain new and useful Improvements in Methods for Removing Liners from Cylinders, of which thefollowing is aspecificatiom ,My saidinvention relates to an improved method for removing liners from shells in which the-y are xed and it is an'object of the invention to provide a cheaper and more expeditious process for removing such liners forI example as are found in ordnance Where the gun body is shrunk on the liner or such liners as are foundi'n various other ysituations where the liner is forced by hydraulic pressure or the like into its seat.

Various methods have hitherto been practiced for securing this result, the usual method being to heat the jacket so as to expand the same and to cool the liner while the jacket ishotso as to procure a certain degree of separationbetween the jacket and the liner, the latter thereupon being pulled out by powerful jacks or like mechanisms.

One detriment of this process has been that where the bore of the jacket is stepped the' material lin the liner is frequently forced out so as to form slight annular ridges and replace a portion of the material of the jacket. The separation between the liner and jacket can not be madegreat enough tovv take care of these lridges and therefore in theact of withdrawing the liner they are dragged over the inner surface of the jacket and form longitudinal grooves or scratches 'in the same. These grooves are afterward removed by reaming. The formation of such grooves is entirely avoided by my process.

In the practice of my invention the gun barrel or other cylinderis placed in convenient position and a heating instrumentality such as an oxyhydrogen llame or the @like lis passed from' end .to end thereof in such a manner .as to heat the (material of the jacketA intensely'along one or more narrow strips extending from end to end of the liner. The liner being in a condition of stress due to the inward pressure of the gun body will immediately exert acompressin'g action on the heated strifps thereby crushin or upsetting thesame romcnd vto end o LrNERs FROM cYLINnnRs.

s, 1922. semi No.' 587,018.

` liner is separated from the jacket from end to end throughout its circu ference after which 1t can' be withdrawn 1n usual manner, either While still hot or after it has v cooled.

rTaking for example a cylinder in which,

the jacket has been shrunk on the liner with such a force as to produce a contraction of .05 of an inch, which liner is to bev removed, it will be seen that heating two diametrically oppositel strips of the `liner may permit it to shrink just .05 of an inch so that 'its normal-outer diameter willI now correspond to the normal inner diameter of the jacket. If theliner has annular shoulders or ridges thereon such as hereinbefo-re referred to which will prevent its ready re- Y moval after the treatment'indicated I may `provide a heatingk apparatus for heating a larger'number ofJ strips through the length of the liner, as for examplenfour or six strips. In this way a reater reduction in size will be provided. n s'ome cases I may find it desirable to subject the entire interior surface of the"line'r to an intense heat area of the liner instead of being divided between' a small number of longitudinal strips. j

The theory 'of my invention, so far as understood, may be stated as follows: Intense-heat is applied to a surface of a cylinder, usually the inner surface, to such a degree that the metal flows and becomes upset so that the thickness of the cylinder wall is permanently increased but the diameter of the cylinder, both 'internally and externally, is permanently `decreas'edf As aboveexplained the heat is ordinarily applied by means of one or more electrodes providing electric arcs whereby arcs along the cylinder wall can be 'heated rapidly throughout its thickness. At the Sametime it appears that the, metal adjacentthe elec- 'trode'will heat more rapidly than that more remote and will break down and iow sooner to a sullcient extent tobecome thus upset. This is of importance especially when the cylinder is not under external compression. The action of the metal is as ifthere were a fulcrum at the extreme point of penetra- .,tion of theh'eat with-the heated metal prying or pulling laterally about said fulcrum.

the liner. This gives the result that .the`This would bend the metal about the full1 0 80 I thereby permitting the compressing effect of the jacket to be exertedover the entire crum ity were -not for the softening upsetting of the-heated portion. Whiletlns explanation `is the best'fIgam. able to give at` this time it is not- .to be understood-.as limiting. my invention in any way,:the essence which are made a part hereof and on whichsimilar reference characters indicate. similar parts, y l

Figure 1 is a longitudinalv section illustrating the use of my invention,` ligure 2 al cross secti'on'fof Figure f 1, an

means of different character.`

l In the drawing reference character 10 '1ndicates thc'outer jacket of 'a gun barrel havving a .hner 11.` An Oxy-acetylene burner removed 12 having two or more branches 13, an inner tube 14 for acetylene andan outer tube 15v for oxygen is inserted endwise into the barrel and is moved endwise of the same as indicated. The heat of the Oxy-acetylene flame isapplied directly to the inner periph- -ery of the .liner and as the burner moves from end to end of the barrel narrow sections of the liner, indicated at 16, will be heated to such an extent that the compression of the jacket acting on the liner will upset the metal in these narrow sections and cause' thesesections to become some-f what thicker and shorter in the direction', of the circumference of the liner. After removal of the burner the liner and more particularly the 'upset sections will 'cool caus- .mg Afrom the' inner wall Aof the jacket leaving an annular s jacket an the liner. The liner may now be by any of the conventional means in a ready and expeditious manner. It will be obvious that I am not limited to any particular number of burners nor to movement in a straight line from end to end of-the gun or other device. As already stated the movement may be along spiral lines or any other' preferred lines. The heatingof narrow annular zonesl vfor example, at spaced intervals through the length of the liner has been foundvery efficacious, it being deemed desirable to heat about 28 per cent 'or more Furthermore the effect being the same whether the zones are all heated at once or successively with Y lany desired interval of time between sucoessive operations. f y

. It will also be evident that I am not limited to'any particular heating means, eleclindery or bushing -an electric" heating Figure 3,- a cross scctionshowing heating the liner to contract andV spring away.

ace o'r crevice at. 17 between the trical heating means being in m'any cases-f even better than the gas-heater. shown in Figures. 1 and. 2. One reason for this is yhat the great accumulationlof heat in a long tube interferes with .the mixture of gasesand v's liable to eause'the flames of the different burners vto A .-p. or be extinguished and relighted at intervals thereby heating the tube irregularly and'leaving'..

high andlow places on the outside of the liner which score the jacket when the two are separated. In Figure 3 I have shown devicel such as is not opento the objectionstated. The heat may be verv accurately controlled and may kbe gauged by means of pyrometers on the out.

s i ye ofthe gunkor other cylinder to insure againstdamage-to the. jacket by local overheating. The carbons 17 are'- 1 arcuate in form and'l'nay be `vthree' in number, preferably covering a large part'of the inner periphery of the liner. One wire is connected to the liner and a flaming arc is thus formed between each carbon and the liner, the heating devices being moved along the jacket at appropriate speed. The carbons are springpressed outwardly in sockets 18 and are rctracted by a solenoid. after the manner of those in the arc-lamp.

Vith eitherv system. if'one operation does v.not afford sufficient clearance'another set of being quick, localized heating with high temperature devices under' low pressure ina manner not to change thel character of the metalin the jacket.

As above indicated I self to the application of this process for ordnance alone but may also use the same ill) first, orthe entire. liner may be heatedas preferred, the .essential features do not limitmyon hydraulic cylinders o'r other apparatus where liners are shrunk or pressed or other-l wise forced very firmly into place so `as to Y be difiicult to remove. l v

Various other modifications of my in.-

vention will occur to those skilled in the art.

For example it is not essential .that the.

strips referred-'to'shall extend precisely in straight lines from one en d of the cylinder `to the other but they may 'be somewhat curved orspiral if 'this is found desirable.

Therefore I do not limit myself to the precise steps'outlined above, but only as indi-v cated in the appended claims. v v

As a slightly modified development of my invention I may mention that it serves exl cellently for shrinking cylinders or cylindrical bodies. In one example of such an operation I have subjected a rough cylinder of vmetal of substantiallength and diameter to a general heat at its lnner periphery and then .suddenly cooled it from the outside by the application of water. It will be understood that various methods-of heating and art and that a comparatively low temperature for the general heat mentioned, as from 600 to 700 degrees, will sullice for my purpose in most instances.

Having thus fully described m said invention, what I claim as new an desire to secure by Letters Patent, is:

1. A process of permanently changing the diameter of a hollow metal cylinder by applying to one peripheral surface only heat suicient to cause upsetting of the metal While keeping the other peripheral surface relatively cool, substantially as set forth.

2. A process of removal of a liner from a jacket holding the liner in compressed relation by the application to the inner surface of the liner of heat suilicient in degree to cause'the metal of the liner to flow and be upset and thus cause a permanent contraction in the diameter of the liner, substantially as set forth.

3. A process for removal of a liner from a jacket holding the liner in compressed relation by the application at localized points on the inner surface of the liner of heat sufficient in degree to cause the metal of the liner to flow and be upset and thus cause a permanent contraction in thev diameter of the liner, substantiallyas set forth. y

4. A 'process for removal of a liner from a jacket holding the liner in compressed relation by the application to the inner surface of the liner along parallel strips of said surface of heat suicient in degree to cause the metal of the liner to flow and be upset and thus cause a permanent contractionin the diameter of the liner, substantially as set forth.

5. A process for removal of a liner from a jacket holding the liner in compressed relation by the application to the inner surface of the liner along one or more longitudinal strips of said surface of heat sulicient in degree to cause the metal of the liner to flow and be upset 'and thus cause a permanent contraction in the diameter of the liner, substantially as set forth.

6. A process of removal of a liner from 'a jacket holding the liner in compressed relation by the application to the inner surface of the liner along parallel longitudinal strips of said surface of heat sufficient in degree to cause the metal of the liner to flow and be upset and thus cause a permanent contraction in the diameter of the'liner, substantially as set forth.

7. A process of removing liners from ordnance wherein such liners are held under compression by applying to the inner surface of a liner along one or more narrow strips thereof heat sufficient in degree to cause permanent contraction of the liner, allowing the liner to cool, and thereafter forcing the liner out of its forth.

In witness whereof, yI have hereunto set my hand and seal at Washington, District of Columbia, this 8th day of September, A. D. nineteen. hundred and twenty-two.

WILLIAM R. WOOD. [L s] Vitnesses:

CHAs. E. RronnoN, E. W. BRADFORD.

jacket, substantially as set 

